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Novel Magnetometers Flight Experiment Conceptual Design Review - Draft. Boston University Mag Dogs Team December 3, 2008. Novel Magnetometers Flight Experiment - Science. Design, assemble, and test two COTS, solid state 3-axis magnetometers with controller, data storage and power:
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Novel Magnetometers Flight ExperimentConceptual Design Review - Draft Boston University Mag Dogs Team December 3, 2008
Novel Magnetometers Flight Experiment - Science • Design, assemble, and test two COTS, solid state 3-axis magnetometers with controller, data storage and power: • Honeywell HMR2003 - anisotropic magneto-resistance • Aichi Micro Intelligent AMI302 - giant magneto-impedance • Compare directly the X,Y,Z flight readings of both magnetometers • Measure EMI from the chips (Honeywell has bias straps and Aichi bias coils). • Honeywell device was proposed for a University of Colorado small satellite design in 2003, but we have found no other evidence of its use in space flight. • Aichi chip is under study by the US Navy for navigation of autonomous marine vehicles. We could find no record of the Aichi chip being used in space.
Honeywell Aichi BU Magnetometers Mont Alto Controller A/D Data Card Power G-switch Launch safing
Subsystems • Sensor 1 Aichi • Sensor 2 Honeywell • Power (Battery + Regulation) • Controller • Sequencing of sensors • Data A/D conversion • Storage to SD card
Sensors – Aichi AMI302 Magnetometer Sensing technology Based on Magneto-Impedance effect of amorphous magnetic wire Range of measurable magnetic flux density: -2 to +2 gauss 3 sensors for length, width, and height (X, Y, Z) Inputs and Outputs: Unit: mm
Sensors – Aichi AMI302 Magnetometer • Supply Voltage: -0.3 to +6.5 VDC • Maximum Supply Current: 200 mA • Approximately 1% duty cycle on this peak current • Operating Temperature: -20 to +85°C • Magnetic Characteristics • Operating Test Conditions • Ambient Temperature: 25°C • Power Supply: 3 VDC • 10 μF ceramic capacitor between Power Supply and Ground
Sensors - Honeywell HMC2003 Magnetometer Sensing technology Anisotropic magneto-resistance Range of measurable magnetic flux density: -2 to +2 gauss 3 sensors for length, width, and height (X, Y, Z) One output for each direction (Xout, Yout, Zout)
Sensors - Honeywell HMC2003 Magnetometer • Supply Voltage: 6 to 15 VDC • Maximum Supply Current: 20 mA • Operating Temperature: -20 to +85°C • Magnetic Characteristics • Operating Test Conditions • Ambient Temperature: 25°C • Power Supply: 12 VDC • Set/Reset switching is active
RCM4300 RabbitCore Stores up to 1GB of information with its miniSD memory card Runs at 58.9MHz 20 parallel digital I/O lines 8 channel analog input with 12 bit resolution Maximum asynchronous transfer rate =Clk (58.9MHz)/8 4 PWM registers with 10 bit counter and priority interrupts Input/Output: 3 Inputs from Aichi - X axis / Y axis / Z axis output from Aichi 3 Inputs from Honeywell - X axis / Y axis / Z axis output from Honeywell
RCM4300 RabbitCore cont. Aichi Use timer to iterate outputs Iterate outputs from RabbitCore to obtain readings from different from differerent axes channels on Aichi Different channels for x, y, and z axes Take input and pass through A/D converter from each Aichi channel Store converted values onto SD flash memory for future use Honeywell Use timer to constantly pull Honeywell for all x, y, and z axes simultaneously Stores the data from each data on a separate place on the SD flash memory Each axes represents a separate output pin from chip Use A/D converter to store as value and store converted value on flash
Science Experiment Timing Normal 1 H A M 5 Mins EMI 1 ~H A M 30 Sec Normal 2 H A M 3 Mins Start at Launch Key: H - Honeywell A - Aichi M - Memory(rabbit) EMI - Electromagnetic Interference EMI 2 H ~A M 30 Sec Safe ~H ~A ~M End Normal 4 H A M 10 Mins Normal 3 H A M 3 Mins EMI 3 ~H ~A M 30 Sec
Test Experiment Timing Normal 1 H A M 5 Sec EMI 1 ~H A M .5 Sec Normal 2 H A M 3 Sec Start Key: H - Honeywell A - Aichi M - Memory(rabbit) EMI - Electromagnetic Interference EMI 2 H ~A M .5 Sec Safe ~H ~A ~M End Normal 4 H A M 10 Sec Normal 3 H A M 3 Sec EMI 3 ~H ~A M .5 Sec
Data Flows • 2 sensors, 4 data sources, housekeeping • 12 b/sample on Rabbit RCM4300 • Slow change in Earth’s field over flight • Changes from spin of rocket (<10 Hz) • Sample 10 pts/cycle or 100 Sa/s • Estimated flight 22.5 min or 1350 s • 135k Sa x 4 x 12b/Sa = 6.48 Mb = 0.8MB • Well within low-end SD card capacities
Testing • Electrical systems operation • Timing test for sequencing • DAQ test with sensors • SD card storage and retrieval • Sensor operation • Earth field testing • Helmholz coil testing of boards • Power operation • Charging/discharging • Voltage regulation and distribution
Parts & Vendors • Aichi AMI302 (3 on hand from Aichi; two week order time) • Honeywell (2 on hand; distributors; 2 week order time) • PCB turnaround (5 business days) • PCB Assembly for Aichi (10 business days) • Rabbit Core 4300 (Dev kit on hand) • Miscellaneous DigiKey/Newark parts
RockSat Payload Canister User Guide Compliance • Sensor board ~15 cm x 15 cm x 2 cm; < 150 g • Rabbit board ~ 5 cm x 8 cm x 1 cm; <100 g • Battery ~ 6 cm x 10 cm x 2 cm; <150 g • (Easily reside in ½ canister or even ¼ height) • Will follow G-switch and Rocket wire protocol • Independent of PSMA system
Shared Can Logistics Plan • Penn State Mont Alto - Boston University • Each system is independent • Structural interfacing (PSMA)
Management Dr. Michael Ruane Professor, ECE Dept., Boston University 8 St. Mary's Street, Boston, MA 02215 Phone: 617-353-3256 617-353-6440 fax E-Mail: mfr@bu.edu Dr. Siegfried Herzog Penn State University at Mont Alto Assistant Professor of Mechanical Engineering 1 Campus Drive Mont Alto, PA 17237 Tel (717)-749-6209 Fax (717)-749-6069 E-Mail: hgn@psu.edu
BU Student Teams • Sensors – Aichi – Shawn Doria • Sensors – Honeywell – John Gancarz • Power – Tracy Thai • Rabbit Controller – Andy Lee • Mechanicals – Jim Thumber • Software/Simulations/Analysis – TBD • Nanosat teams join after January 15
Conclusions • BU Mag Dogs Team is closing out its semester and catching up to the RockSat schedule • We have an enthusiastic group of students, a lab space for work, and a Nanosat team becoming available in January • Our experiment is building on a sensor board from USERS and a microcontroller DAQ system